Modulation of ventricular spiral-wave reentry by cardiac ion channel blockade

心脏离子通道阻断对心室螺旋波折返的调节

• 批准号: 13670702
• 负责人: HONJO Haruo
• 金额: $ 2.05万
• 依托单位: Research Institute of Environmental Medicine, Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13670702/
• 关键词: spiral reentry; optical mapping; ventricular tachycardia; antiarrhythmic drug; anisotropic conduction; curvature effect; excitable gap; 活動電位; 坑不整脈薬; スパイラルリエントリー; ブロックライン

It is widely accepted that functional reentry plays an important role in the initiation and maintenance of ventricular tachycardia/fibrillation (VT/VF). Various concepts including "leading circle", anisotropic reentry and spiral-type excitation have been proposed to explain the functional reentry in the heart but its precise mechanisms remain to be elucidated. We investigated dynamics and pharmacological modulation cf VT by high-resolution optical mapping. Two-dimensional subepicardial ventricular myocardial sheet (〜1 mm in thickness) of the Langendorff-perfused rabbit heart was made by cryoablation of the endocardial side of the left ventricle. The heart was stained with di-4-ANEPPS (2 μM), and fluorescence images of theventricular myocardium were obtained via a high-speed video camera (temporal and spatial resolutions of〜1.3 ms and 〜0.1 mm, respectively). VT induced by cross-field stimulation was often the result of single reentry around a "Z"-shaped functional line of block. The cen … More tral segment of the block line, which was independent of the myocardial fiber direction, was associated with an abrupt phase-shift of the action potential. Small amplitude double potentials without electrical diastole were obtained at the central block line suggesting "leading circle"-type electrotonic interaction. The two terminal segments were caused by localized conduction delay around pivot points of the rotation and these lines were always parallel to the myocardial fiber direction. Source-to-sink imbalance created by wavefront curvature combined with tissue anisotropy may be responsible for the localized conduction delay around the pivot paints. Blockade of Na^+ channels by pilsicainide, disopyramide and cibenzoline extended the terminal block lines through the enhancement of the localized local conduction delay and caused appreciable electrical diastole (excitable gap) in the circuit except around pivot points. These results suggest that functional reentry in the two-dimensional ventricular myocardium is determined by wavefront-tail interaction and source-sink imbalance caused by wavefront curvature and tissue anisotropy. Less

人们普遍认为功能性折返在室性心动过速/室颤(VT/VF)的发生和维持中起着重要作用。前导圈、各向异性折返和螺旋型兴奋等概念已被提出用于解释心脏功能性折返，但其确切机制尚不清楚。我们用高分辨率光学标测技术研究了室性心动过速的动力学和药物调控。通过冷冻消融左心室内膜侧，制作了兰根多夫灌流的兔心脏心外膜下二维心肌片(厚度约1 mm)。心脏用2μM的di-4-ANEPPS染色，用高速摄像机(时间分辨率为~1.3ms，空间分辨率为~0.1 mm)获取心肌的荧光图像。交叉场刺激诱发的室性心动过速往往是单次折返绕“Z”型传导阻滞功能线的结果。The Cen…与心肌纤维方向无关的阻滞线上更多的Tral节段与动作电位的突然相移有关。中央阻滞线出现无舒张期的小幅度双电位，提示存在“先导圆”型电张力相互作用。这两个末端段是由旋转枢轴点周围的局部传导延迟引起的，且这些线始终平行于心肌纤维方向。波前曲率和组织各向异性所造成的源汇不平衡可能是枢轴涂料周围局部传导延迟的原因。用匹西卡胺、异丙基吡胺和西比林阻断Na~+通道，可使局部传导延迟增加，延长终末阻滞线，除枢点周围外，还可引起明显的电舒缩(可兴奋间隙)。这些结果表明，二维心肌的功能性折返是由波前-波尾相互作用和由波前曲率和组织各向异性引起的源汇失衡决定的。较少

项目成果

Motoki Nihei et al.: "Na+ channel blockade causes a prolongation of electrical diastole during spiral-type reentry in the ventricle"Environmental Medicine. 46 in press. (2002)

Motoki Nihei 等人：“Na 通道阻断导致心室螺旋型折返期间电舒张期延长”环境医学。

山本 充 他: "心室スパイラル・リエントリーに対するI群坑不整脈薬の作用"Progress in Medicine. 22. 2563-2570 (2002)

Mitsuru Yamamoto 等人：“I 类抗心律失常药物对心室螺旋折返的影响”医学进展 22. 2563-2570 (2002)。

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Jintaro Shibata 等人：“心室颤动和除颤的机制”ICU 和 CCU。26. 233-240 (2002)

柴田 仁太郎 他: "心室筋レベルでの心室細動と電気的除細動"ICUとCCU. 26. 233-240 (2001)

Jintaro Shibata 等人：“心室肌水平的心室颤动和电复律”ICU 和 CCU。

佐久間一郎 他: "高輝度発光ダイオードと高速度ビデオカメラを用いる心臓膜電位マッピングシステム"心臓. 33. 439-448 (2001)

Ichiro Sakuma 等人：“使用高强度发光二极管和高速摄像机的心脏膜电位绘图系统”Cardiac。 33. 439-448 (2001)